1. Field
The present disclosure relates to a rolling device for a secondary battery.
2. Description of the Related Art
In general, batteries are classified into primary batteries and secondary batteries. Unlike primary batteries, secondary batteries are rechargeable. The secondary batteries have come into widespread use for advanced electronic apparatuses, e.g., cellular phones, notebook computers or camcorders.
In particular, lithium secondary batteries operate at a voltage of 3.6 V and are widely used as power supplies for electronic apparatuses. Lithium secondary batteries have been increasingly and extensively researched and developed because they have operating voltages that are approximately three times higher than operating voltages of nickel-cadmium (Ni—Cd) batteries or nickel-metal hydride (Ni-MH) batteries, and have high energy density per unit weight. Such lithium secondary batteries generally use lithium oxide as a positive active material and a carbonaceous material as a negative active material. In addition, lithium secondary batteries are manufactured in various shapes, and representative examples thereof may include cylindrical batteries, prismatic batteries, and pouch-type batteries.
Generally, a lithium secondary battery includes an electrode assembly, a lithium secondary battery case which accommodates the electrode assembly, and an electrolyte solution which is inserted inside the lithium secondary battery case and allows lithium ions to move. The electrode assembly includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode to prevent a short therebetween and to allow an electrolyte solution or ions to move.